Americans, more than most people, believe that history is the result of individual decisions to implement conscious intentions. For Americans, more than most people, history has been that.... This sense of openness, of possibility and autonomy, has been a national asset as precious as the topsoil of the Middle West. But like topsoil, it is subject to erosion; it requires tending. And it is not bad for Americans to come to terms with the fact that for them too, history is a story of inertia and the unforeseen.